P&F 4 - Asthma Candidate Genes Identified by Genome-Wide Association Analysis Confer Susceptibility to or Protection from Rheumatoid Arthritis (RA) PI: Peisong Gao, M.D. A major goal of this study to determine the extent to which single nucleotide polymorphisms (SNPs) in novel asthma genes are similarly associated with RA according to the hypothesis that there might be common underlying genes for both RA and asthma, likely involved in various inflammatory pathways. To date we have completed analyses of 1,000 African American asthma cases and healthy controls and 1,000 African Caribbean family-based populations. We are generating a list of candidate genes based on the significance (P value) and replication across both an independent African American populations and an independent population of asthmatics from the U.K. (~3,000) as part of our collaboration with partners at the Heart &Lung Institute in London. These candidates will be prioritized for genotyping individuals with rheumatoid arthritis. A total of 384 SNPs will be selected for generating a custom 384-plex panel and genotyped using the BeadXpress platform. This panel can be used from 1 to 480 samples with the same expenses. Thus, instead of the original we proposed to include 200 diagnosed RA patients who meet the American College of Rheumatology (ACR) criteria for the classification of RA, we are collecting more samples (-400) from our ongoing RA studies including a pilot study and a large cohort study at Johns Hopkins Arthritis Center (ESCAPE RA) trial. We believe that we will generate a significant amount of data (384 x 400) for analyses of genetic association with RA and relationship between two common diseases, asthma and RA.